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Placenta Previa

Placenta previa is a condition that occurs when the baby’s placenta partially or totally covers the mother’s cervix.

It occurs in about 1 out of every 200 pregnancies, according to the March of Dimes. If placenta previa occurs early in the pregnancy, it will often resolve itself; however, it can result in severe complications if it occurs later in the pregnancy. Placenta previa during labor and delivery can put mother and baby at risk.

Placenta icon

Placenta previa has three types, according to the American Pregnancy Association:

What causes placenta previa?

The exact cause of placenta previa is unknown; however, certain factors put women at increased risk of developing placenta previa.
According to the March of Dimes, risk factors for placenta previa include:

Placenta Previa Symptoms

Often, placenta previa has no symptoms. When women do have symptoms, the primary symptom is painless vaginal bleeding during the second half of the pregnancy. Bleeding can be severe and, in some cases, life-threatening. It also may create the need for an emergency C-section. Women who have vaginal bleeding during the second and third trimesters should call their health care provider right away.
Other signs and symptoms of placenta previa are:
Pregnant woman

How is placenta previa diagnosed?

Doctors diagnose placenta previa through the use of an ultrasound, a prenatal test that uses sound waves. Sometimes doctors use a combination of abdominal and transvaginal ultrasounds.
If placenta previa is found in the second trimester, doctors will often repeat the test later in the pregnancy to see whether the cervix is still blocked. Usually, a low-lying placenta will move upward and resolve itself before the third trimester.
Doctor testing a pregnant woman

What is the treatment for placenta previa?

The treatment depends upon various factors, including the stage of pregnancy, the overall health of the mother and baby, and the seriousness of the bleeding.
If the condition is diagnosed early in pregnancy and asymptomatic, the health care professional may continue to monitor the situation without treatment.
Your doctor will avoid a vaginal exam if he or she suspects placenta previa. They may also recommend that you avoid travel, strenuous exercise, and standing for more than four hours to prevent contractions and bleeding. If the placenta previa is diagnosed after 20 weeks of gestation, the doctor may also recommend you avoid sex.
If you are bleeding, doctors will have you go to the hospital for monitoring and may prescribe you medications. If bleeding is severe, you may require a blood transfusion.
In cases where the placenta covers the cervix, the mother will undergo a Cesarean section when the baby can be delivered safely. Doctors may conduct amniocentesis to determine whether the baby’s lungs are fully developed.
Tocolytics may be prescribed to slow the contractions and delay labor.
If bleeding continues to be severe, the doctor will do the Cesarean delivery immediately, even if the baby is preterm.

What are the possible complications?

Placenta previa is generally not a problem when it occurs early in pregnancy if the placenta expands and lifts on its own as the fetus grows. However, significant complications can result if it appears in the third trimester.

Preterm Birth

The mother may experience severe bleeding during the pregnancy. In this case, the doctor may have to schedule an emergency Cesarean delivery before 34 weeks of pregnancy. The premature baby is at greater risk for breathing issues and birth injuries such as cerebral palsy and hypoxic-ischemic encephalopathy.


Life-threatening bleeding can occur during labor, delivery, and post-delivery. Postpartum hemorrhages cause 12 percent of maternal deaths in the United States, according to American Family Physician. Doctors often prescribe medication or transfusions to treat hemorrhages.

Placenta Accreta

Placenta previa increases the risk of placenta accreta. Placenta accreta occurs when the placenta grows into the uterine wall. Instead of detaching from the uterine wall after childbirth, all or part of the placenta remains attached.

Placenta accreta also can cause severe blood loss. To control this severe bleeding, the patient might require a hysterectomy — full removal of the uterus. Placenta accreta can also require preterm delivery, leading to complications such as fetal hypoxia, another effect of oxygen deprivation. Fetal hypoxia can result in significant issues of brain and neurological function, according to Frontiers in Neuroscience.

Placental Abruption

Placental abruption occurs when the placenta “partly or completely separates from the inner wall of the uterus before delivery,” according to the Mayo Clinic. It also can decrease or block the baby’s supply of oxygen and cause heavy bleeding for the mother. Placental abruption is more likely in cases of placenta previa.

Preventable Causes of Birth Injuries Associated with Placenta Previa

Placenta previa requires careful diagnosis and treatment to avoid injury to the baby or mother. Sometimes physician inattention or error is to blame for injuries stemming from the condition.
The following medical errors can cause injury to the mother or baby when placenta previa is present:

Seek Help

Raising a child who has suffered complications because of oxygen deprivation during birth can be challenging. The child will need special medical care to achieve the best outcome.
If you’ve lost a loved one because of complications from hemorrhaging due to placenta previa, the grief can be devastating. Not only have you lost the companionship of someone you love, but you may also have lost income or need to pay for child care or other services they might have provided

We at Birth Injury Center understand the challenges of life without a partner or with a special needs child. If you think medical malpractice may have caused injury to you or your baby, contact us today.

Doctor smiling at the camera

Written by:
Birth Injury Center Team

The Birth Injury Center aims to create informational web content and guides to help women and their families seeking support and guidance for birth injuries caused by medical negligence. All of the content published across The Birth Injury Center website has been thoroughly investigated and approved by medical expert Natalie Speer, RNC-OB, Attorney Ryan Mahoney, and Attorney Rick Meadows.